Liquid containment berms are used to prevent hazardous fluids from entering the environment from the spillage of the fluids during, for example, the loading and unloading of storage containers and transport vehicles, wash-down of equipment and vehicles, and repair/maintenance of equipment and vehicles. Conventional containment berms may be intended for permanent use, while others are designed to be portable. One type of permanent containment berm is disclosed in U.S. Pat. No. 5,820,297, which is incorporated herein by reference. Such permanent berms are built from multiple elongated strips connected by corner pieces that are secured to a floor or ground by an adhesive such as caulking. Examples of portable containment berms are disclosed in U.S. Pat. Nos. 5,316,175, 5,762,233, 6,092,686 and 6,880,720, which are incorporated herein by reference.